U.S. Pat. No. 6,317,448, issued to Das, et al. on Nov. 13, 2001, titled BANDWIDTH ESTIMATING TECHNIQUE FOR NARROW BAND LASER, based upon an application Ser. No. 09/405,615, filed on Sep. 23, 1999, and U.S. patent applications Ser. Nos. 10/012,002, filed on Nov. 30, 2001, entitled VERY NARROW BAND TWO CHAMBER HIGH REPETITION RATE GAS DISCHARGE LASER SYSTEM, with inventors, Knowles, et al., published on Oct. 24, 2002, Pub. No. 20020154668, and 10/026,676, filed on Dec. 21, 2001, entitled FOUR KHZ GAS DISCHARGE LASER SYSTEM, with inventors Wittak et al., published on Jun. 26, 2003, Pub. No. 20030018072, and 10/056,619, filed on Jan. 23, 2002, entitled LINE SELECTED F2 CHAMBER LASER SYSTEM, with inventors Knowles, et al., published on Oct. 24, 2002, Pub. No. 2002/0154671, and Ser. No. 10/141,216, filed on May 7, 2002, entitled LASER LITHOGRAPHY LIGHT SOURCE WITH BEAM DELIVERY, with inventors Klene, et al., published on Dec. 19, 2002, Pub. No. 20020191654, and Ser. No. 10/187,336, filed on Jun. 28, 2002, entitled SIX TO TEN KHZ, OR GREATER GAS DISCHARGE LASER SYSTEM, with inventors Watons, et al., published on Jan. 16, 2003, Pub. No. 20030012234, and Ser. No. 10/243,102, filed on Sep. 13, 2002, entitled TWO CHAMBER F2 LASER SYSTEM WITH F2 PRESSURE BASED LINE SELECTION, with invention Rylov et al., published on Jul. 24, 2003, Pub. No. 20030138019, and Ser. No. 10/210,761, filed on Jul. 31, 2002, entitled CONTROL SYSTEM FOR A TWO CHAMBER GAS DISCHARGE LASER, with inventors Fallon, et al., published on Feb. 13, 2003, Pub. No. 20030031216, and Ser. No. 10/036,727, filed on Dec. 21, 2001, entitled TIMING CONTROL FOR TWO-CHAMBER GAS DISCHARGE LASER SYSTEM, with inventors Ershov et al., published on May 29, 2003, Pub. No. 20030099269, while, except for the referenced patent, not prior art to the present application discuss existing gas discharge lasers and wavemeters and other metrology devices used with such lasers. The above referenced patent and applications are all assigned to the assignee of the present application and the disclosure of each of which is hereby incorporated by reference.
There exists a need for improved metrology equipment for gas discharge lasers operating at the repetition rates discussed in the above referenced applications and beyond those rates and especially for such lasers configured in a MOPA system with the higher power outputs available.